Improvement in screw-cutting dies



J. P. G. RIDER. Screw-Cutting Die.

Patented Aug 12, I879.

.PEI'ERS, PHOTOLITNOGRAPHER. WASHINGTON D C UNITE STATES PATENT OFFICE.

JOHN F. O. RIDER, OF SOUTH NEW MARKET, NEW HAMPSHIRE, ASSIGNOR TO HELEN A. RIDER, OF SAME PLACE.

IMPROVEMENT IN SCREW-CUTTING DIES.

Specification forming part of Letters Patent N0. 218,402, dated August 1'2, 1879; application filed January 19, 1877.

To all 'whom it may concern:

Be it known that I, JOHN F. O. RIDER, of South New Market, in the county of Rockingham and State of New Hampshire, have invented a new and useful Improvement in the Construction of Dies and Taps for Cutting Screw-Threads, which improvement is fully set forth in the following specification and accompanying drawings, in which Figure l is a plan View of a screw-threading (lie with my improvemena'showing Variousshaped cutters inserted; Fig. 2, an elevation of the same; Figs. 3 and 4, sectional "iews.

A is the blank or stock, in which the small cutters b c d 0, of any desired shape, are inserted.

I form the blank A with openings or slots therein to receive the cutters b c d e, and weld the cutters securely into the slots so formed in the blank. When so constructed the implement can be made at a greatly-reduced cost and much lighter than the ordinary tool.

By this method of construction I am able to insert steel cutters in iron blanks or re-- 

